No volcanoes in Alberta, so where does the Obsidian come from?

When working close to an obsidian source (i.e. volcanoes), archaeologist will regularely find obsidian tools and debitage. However, in the boreal forests of northern Alberta, obsidian is a rare find indeed. So to find any evidence of it at all is pretty significant. Volcanic glass, or obsidian, is one of the sharpest naturally occurring materials on earth. It is sometimes used by surgeons who require a cutting edge that is much thinner and sharper than a stainless steel scalpel. Not only is obsidian extremely sharp, but it is also relatively easy to flint knap and is used by many beginners trying to learn this ancient skill. These features made obsidian a highly valued knapping material.

Pre-contact peoples fashioned various tool types from it, such as knives, projectile points, or composite tools. One method of knapping obsidian was blade core technology. This method involves preparing an obsidian core so that a series of small blades can be removed. This method minimizes the amount of material that is wasted and allowed people to quickly reproduce blades that were a similar size and shape. These blades were then hafted to a bone or stick to create a cutting utensil. To create larger tools, obsidian would have been knapped using normal methods as well.

Photo credit: B. Bernard

Last summer, Tim and I were surveying some forestry cutblocks at the base of the southern slopes of the Marten Hills, east Slave Lake. During the screening process, I had targeted a series of small knolls that overlooked a muskeg. These knolls were close to the headwaters of the Fawcett River, where a natural pass would have allowed people to easily traverse through the hills. Tim and I walked to the top of the highest knoll and started digging test pits.

Brian at the GiPk-3 hill top

We were completely shocked when my first test contained an obsidian blade. At this point we were extremely excited, and were sure that we had just found a crazy site. However, even though we dug 40+ test pits, we never found another artifact. The site turned out to be an isolated find. Nuts!

So if there are no volcanoes in Alberta, where did this obsidian blade come from? Luckily, advances in technology allowed us to quickly solve this question. During his Master’s degree, Tim obtained a license to operate a pXFR analyzer (portable X-Ray Fluorescence), so Tree Time Services Inc. rented one of these devices. Other obsidian artifacts recovered by Tree Time services were all found to come from south of the U.S. border. However, the results of Tim’s analysis suggests that the blade was made of obsidian from Mt. Edziza, British Columbia.

Results of pXRF, showing range for various volcanic sources.

That means that this piece of stone had been transported/traded by Pre-contact peoples over a distance of 1700 km! At 10 km travelling distance in a day (on foot), that is 170 days, or almost 6 months. Mt. Edziza obsidian has never been found in the Lesser Slave Lake region, however is is somewhat common in the Peace Region in northwest Alberta. GiPk-3 represents one of the furthest known Mt Edziza obsidian finds from its source. Although Tim and I were disappointed that we didn’t find more artifacts, this single find provided evidence for trade networks that spanned vast distances long before European contact.

Image Credit: Todd Kristensen

Projectile Point

Projectile points come in many shapes and sizes ranging from large paleolithic spear points to small protohistoric arrow heads to even smaller “toy arrow heads”. This artifact type is a stone that has been shaped using flint knapping techniques to create a sharp triangular and aerodynamic tip that is attached to a wooden shaft that can be propelled through the air by throwing by hand, atlatl, or bow, to hunt game. This is an important artifact type as over time the styles of points changed allowing us to use the style to estimate the time period a site was occupied.  This particular point is a Besant style dart point, which dates to approximately 2,500 -1,350 BP.

Atlatl

An atlatl is a throwing stick with a small hook used to throw darts (projectiles). It allowed the hunter or warrior to create more leverage to increase the speed and distance of the dart. This weapon was used throughout North America including Alberta, approximately between 7,500 and 1,350 B.P.

Atlatl in action!

Note the size of the atlatl to the size of the throwing dart

 

Spokeshave

A spokeshave is a type of formed tool that was used to scrape and/or smooth wooden shafts or handles such as on spears, darts and arrows. It is typically identified by the inward curving edge. This edge typically has small flakes removed from use or from shaping it into the curve prior to use.

Knapping / Flintknapping

The process of creating stone tools through lithic reduction (by removing stone chips).  A hammer (such as a stone or antler) is used to strike the core rock in order to remove smaller pieces.  The core is either shaped into a specific tool, like a biface, or the flakes that have been taken off are used or shaped into something specific, like a projectile point.

Surface Exposure

Surface exposures are areas where there is no vegetation and the mineral soils are visible. These can occur naturally (areas of slumping, beaches, blow-out, or other natural erosional processes), or be caused by human activity (ATV trails, furrows created for site prep and skid trails just to name a few). Surface exposures can be great for covering a lot of ground during survey.

Calcined Bone

When bone is burnt by a fire it can undergo a range of changes in appearances, such as calcining. Calcining, characterized by its bright white colour, is caused when bone is burnt at a higher temperatures. The bone can shrink, become more white or chalky in appearance, more fragile and more likely to fragment into smaller pieces. These pieces of calcined bone were collected during the summer of 2017. Calcined bone indicates the presence of a hearth at the site.

Public Archaeology at the Brazeau Reservoir

Public archaeological programs are an excellent opportunity for people with a general interest in archaeology or amateur archaeologists to learn what an artifact is, and to practice the techniques that are used to find and interpret them. Often these programs will have a dig component, where people join for a few days or a week, and learn excavation techniques in units laid out over a buried site.

The Brazeau Archaeological Project (BAP), sponsored in part by Tree Time Services Inc., provides a unique experience. The current sites being surveyed are almost entirely exposed by the continuously fluctuating water levels of the reservoir. This also means that the entire history of the area has been deflated to one level, rather than multiple occupation levels that can be apparent in excavations. The occupation of the Brazeau River by First Nations extends as far back as 12- 14,000 years ago. This allows participants to gain a better feel of how large and spread out an archaeological site can really be. The largest site surveyed so far spans almost 1 km!

Bob Dawe (left) discussing boiling pits. Photo Credit: Jack Brink

The project invites members of the Strathcona Archaeological Society (SAS) to come out for a day or weekend to learn survey and excavation techniques, as directed by experienced or professional archaeologists. As most of the artifacts lay exposed on the surface due to the ever changing water levels of the reservoir, the experience is relaxed, family friendly, and can be conducted over a single day or weekend, rather than a week-long commitment.

Participants surveying, excavating, and generally having a good time!  Photo credit: Top and left – Hilary McDonald; right – Madeline Coleman

Participants learn what features to look for when looking for surface finds, such as material, shape, and modifications. By pairing participants up with experienced archaeologists we can point out the various ways an artifact, such a flake, can look; particularly how it can blend in or really stand out from its surrounding environment. For example, Amandah van Merlin, one of the co-ordinators, picked up a small, indistinct black pebble. The black pebble chert material, however, is a popular flint knapping material. As it turned out, Amandah had found a thumbnail scraper!

A small pebble with a big surprise!  Photo credit: Amandah van Merlin; inset – Madeline Coleman

Public archaeology programs are also a great way to explore new technology or try experiments. One participant brought his drone. He was able to take photos from a bird’s-eye view of the site, providing a totally new perspective on what these landforms look like along the shore, and the distances between the sites. Madeline Coleman, the other co-ordinator, laid out various sizes of brick pieces in order to examine how artifacts are affected by water movement (or perhaps even people).

Ariel view of FfPv-1.  Photo credit: Robert Wambold

Laying out pieces of brick to monitor movement over time.  Photo credit: Madeline Coleman

The project is still in its infancy. The pilot survey in May 2015 occurred over one day and had 9 participants. In May 2016, the survey occurred over two days with over thirty participants joining for one or both days. This past May, there were over 20 participants that joined for the full weekend. In addition, for two days prior to the public survey, BAP worked with University of Alberta field school students. Here they practiced map making, shovel testing, and laying out excavation units.

Outreach is also a very important aspect of a public program, such to First Nations group, schools, and universities. The BAP has recently reached out to Paul First Nation, in whose traditional territory the Brazeau River lies, and whom are active in working to protect their heritage. BAP has also recently partnered with Katie Biittner at Grant MacEwan University to begin a hands-on catalogue experience for university students at Grant MacEwan and the University of Alberta. In addition, the original finders of the site, Sandy and Tom Erikson, worked to create a 3-case display at their hometown school in Edson. The case shows some of the finds and information from the periods they may have originated in.

School display in Edson. Photo credit Sandy Erikson

Core

A core is a larger piece of stone from which many smaller flakes are removed. These flakes are then turned into tools or are utilized as they are. There are many different types of cores, but a common way to describe them is by the direction(s) flakes were removed, or by the shape of the core. For example, unidirectional cores have flakes removed all in the same direction. That has had many stone flakes removed to make other tools.

Obsidian

Obsidian is commonly known as volcanic glass. It forms when a volcano erupts and the lava is cooled extremely quickly, such as when it flows into a water body. In Alberta obsidian is considered to be an “exotic material” because it does not occur here naturally. When we find it here it tells us that people in the past engaged in long distance trade, usually with people in British Columbia or the Yukon. In 2016 Teresa found this lovely obsidian flake at site FaPr-6 located near the community of Caroline.